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Chapter 4. The North American genus Climacoidea Puri, 1956, and the tribe Campylocytherini (Neogene and Quaternary)
40 J. E.HAZELAND T.M.CRONIN
Previous Studies of Reticulocythereis and Climacoidea
Climacoidea was originally described by Puri (1956) from the Caloosahatchee Formation (upper
Pliocene and lower Pleistocene) of southern Florida; C. plueurata Puri, 1956, is the type species
by monotypy. Puri did not assign Climacoidea to any family, stating only that it differed from the
genus Hemicythere in hinge and ornament. The muscle-scar pattern was described as “obscure.”
Howe and others (1961) placed Climacoidea in “family uncertain.”
Swain (1955) described the species Paracytheretta multicarinata from San Antonio Bay, Texas,
and later Puri (1958) assigned Swain’s species to another cytherettine genus, Protocytheretta. Subsequently, Puri (1960) erected the genus Reticulocythereis for the morphologically similar species
R. jloridana. He characterized Reticulocythereis as being bean-shaped, oblong-ovate, and having
a lateral surface with a reticulum, the ridges of which radiate from the center. He also stated that
the hinge in the right valve has a bilobed anterior tooth and a trilobed posterior tooth. Neither
Swain (1955) nor Puri (1960) described or illustrated the muscle-scar patterns of the two species.
King and Kornicker (1970), in an ecological study of ostracodes from Texas bays and lagoons,
assigned Paracytheretta multicarinata to Reticulocythereis rather than to the Cytherettinae because the inner lamella is neither wide nor sinuous as it is in typical cytherettines and because
Reticulocythereis possesses an eyespot. King and Kornicker also noted that R. multicarinata
possesses a distinct alate extension, a feature we believe to have taxonomic significance at the
Keyser (1975a) described Reticulocythereis purii from mangrove swamps of southwest Florida.
Keyser (1975b, 1977, 1978) reported on specimens of Reticulocythereis from southwest Florida,
which he assigned to R.jloridana Puri, 1960. He commented on the similarities between R.jloridana
and R. multicarinata Swain, 1955, and called for detailed study of variation in surface ornament to
determine the relationship between taxa.
Morphology of Climacoidea
Our morphological investigations, coupled with the work of Plusquellec and Sandberg (1969),
show that Climacoidea Puri, 1956, Reticulocythereis Puri, 1960, and Proteoconcha Plusquellec and
Sandberg, 1969, should be considered subgenera within the genus Climacoidea Puri, 1956, and the
tribe Campylocytherini Puri, 1960. Climacoidea (Proteoconcha) possesses a smooth to variably
pitted surface (in some species), C. (Reticulocythereis) has a regular surface reticulation and a
posteroventral alar projection, and C. (Climacoidea) is characterized by extremely strong development of raised, curved carinae. Climacoidea differs from the other two campylocytherine genera
Campylocythere Edwards, 1944, and Acuticythereis Edwards, 1944, in carapace shape, hinge,
normal and radial pores, and details of the muscle scars.
We assign the following species to the three subgenera of Climacoidea:
Reticulocythereis jloridana Pun, 1960
Paracyheretta multicarinata Swain, 1955
C. (Reticulocythereis)foresteri n. sp.
C. (Reticulocythereis)reticulata n. sp.
C . (Climacoidea)
Climacoidea plueurata Puri, 1956
Basslerites giganticus Edwards, 1944
Acuticythereis multipunctata Edwards, 1944
Acuticythereis nelsonensis Grossman, 1967 (= Proteoconcha protea Plusquellec and
North American Tribe Campylocytherini 41
Acuticythereis tuberculata Puri, 1960
Campylocythereconcinnoidea Swain, 1955
Reticulocythereispurii Keyser, 1975 (?= Acuticythereis ruberculata Pun, 1960)
Cythere redbayensis Puri, 1954
Proteoconcha mimica Plusquellec and Sandberg, 1969
Proteoconcha edwardsi Plusquellec and Sandberg, 1969
Proteoconcha jamesensis Hazel, 1983
Proteoconcha costa Krutak, 1978
Females of Climacoidea (Reticulocythereis) are subovate in lateral view, whereas males are
more elongate (Plates 1 and 3), In dorsal view, both sexes are widest behind the middle; females
are wider than males. In contrast to species of C. (Proteoconcha) and C. (Climacoidea), species of
C. (Reticulocythereis) are consistently ornamented by regular reticulation including longitudinal
ridges in the dorsal half. A variably developed posteroventral alate projection, which consists of
a subcircular flat region from which projects a small ala (Pl. 1, fig. 3; P1. 3, figs. 2-6), this alar
is also characteristic of the subgenus C. (Reticulocythereis). The widest part of the carapace is in
region. Although several species of C. (Proteoconcha) sometimes have pitted surfaces (C. (P.)
nelsonensis; C. (P.) multipunctata), this ornament is quite variable within a single population, and
areas of the carapace are often smooth.
Males and females of C. (Climacoidea) are subovate to subquadrate in lateral view; males are
not as high as females (Pl. 1, figs. 1, 4). The subquadrate shape results from the characteristically
strong development of curved longitudinal carinae that overlap the valve margin. Some raised
carinae parallel the valve margin ; the most peripheral carinae project beyond the valve margin
posteroventrally and posterodorsally. Between carinae, the surface is variably reticulate. The
extreme development of the carinae is the major diagnostic feature that distinguishes C. (Climacoidea) from the other subgenera.
Climacoidea (Proteoconcha) was described and illustrated by Plusquellec and Sandberg (1969).
Most species of this subgenus have a smooth valve surface; a few species have weak pitting.
Proteoconcha costa Krutak has minute longitudinal riblets which parallel the valve margins and
minute papillae as secondary ornament (Krutak, 1978). This subgenus lacks the strong reticulum
and alate projection of C . (Reticulocythereis) and the raised carinae of C. (Climacoidea).
Plusquellec and Sandberg (1969) found that among the three campylocytherine genera that they
studied, Acuticythereis has the most normal pore canals, Campylocythere has slightly fewer, and
Proteoconcha has the least. We have found that Climacoidea (Climacoidea) and C. (Reticulocythereis) are similar to C. (Proteoconcha) in having relatively few normal pores, about 80 to 100.
The marginal areas of the three Climacoidea subgenera are very similar to one another, but
differ significantly from those of Campylocythere and Acuticythereis. A shallow anterior vestibule,
limited to the central and anteroventral parts of the inner lamella, is present in all three, in contrast to the very wide anterior vestibules in Campylocythere and Acuticythereis. In Climacoideu,
anterior radial and false radial pore canals number about 15-25, are irregularly spaced, and vary
in length. Conversely, Acuticythereis and Cumpylocythere have many more radial and false pore
canals that are shorter and more regularly spaced (see Plusquellec and Sandberg, 1969, for details).
The close affinity of Climacoidea subgenera is well illustrated in the similarity in hinges (Pl.
5, this paper; Plusquellec and Sandberg, 1969). All possess an amphidont hinge, having a conical
anterior tooth in the right valve sloping rapidly into a deep postjacent socket. The posterior tooth
in the right valve of C. (Reticulocythereis) is more elongate than those in C. (Climacoidea) and C.
(Proteoconcha).The median groove is crenulate in the vertical plane in all three subgenera. Although
Puri (1956) described the anterior right valve tooth of Climucoideu as bilobed and the posterior
tooth as trilobed, no specimens in our collections possess these features. The hinge of Climacoidea
42 J. E. HAZELAND T. M. CRONIN
differs significantly from those of Acuticythereis and Campylocythere, which both have elongate
anterior hinge elements and a much shallower, narrower groove in the right valve (see Plate 5,
this paper; Plusquellec and Sandberg, 1969).
All three Climacoidea subgenera as well as Acuticythereis and Campylocythere have the same
basic muscle-scar pattern, consisting of a near vertical row of four oval to slightly elongate adductor scars, and two frontal scars anterior to the adductors (Text-fig. 1). The dorsal frontal scar
is round, the ventral is larger, elongated, and slightly incised in the middle. Plusquellec and Sandberg (1969) provided a detailed discussion of campylocytherine dorsal and mandibular muscle
scars, which are generally very similar in Acuticythereis, Campylocythere, and Climacoidea. Dickau
and Puri (1976) studied the soft parts of Acuticythereis laevissima Edwards, 1944, and found a
five-jointed first antennae and chitinous supports in the knees of this species.
Note on Cumpylocythereis Omatsola, 1971
Omatsola (1971) proposed the genus Campylocythereis for Holocene species from the Niger
Delta area of the West African coast and placed it in the Campylocytherinae because of its carapace shape, the stated similarity of the dorsal muscle scars to those of Cumpylocythere (both having
divided dorsal muscle scars), and its compound normal pores. However, the value of dorsal muscle
scars in classification is as yet untested. Campylocythereis does have a carapace shape similar to
that seen in the Campylocytherini, particularly some C. (Proteoconcha). However, the frontal and
adductor muscle scars, which are of known taxonomic value (Hazel, 1967; this paper), are unlike
those of known Campylocytherini. Similarly, normal pores are considered by some authors to
be important taxonomic characters for supergeneric categories, yet those of Campylocythereis are
quite different from those of the campylocytherines. All campylocytherini have what Puri (1974)
refers to as Type D normal pore configuration, described as sieve plates having a subcentral small
pore and separate single pores that have a sensory hair (in living material). We are not sure where
in Puri’s classification of pore types those described by Omatsola for Campylocythereis can be
classified, but they are not similar to those seen on our specimens of Campylocytherini, nor on
those illustrated by Puri (1974). Moreover, Campylocythereis has a dorsal adductor scar that
points towards the anterodorsal region, a much elongated and anteroventrally pointing dorsomedian scar, and two ventral adductors that “are in close contact with each other but sometimes
show continuity” (Omatsola, 1971, p. 108). The frontal scars of Campylocythereis consist of one
J-, U-, or heart-shaped scar, or a double or triple frontal scar (Omatsola, 1971). These muscle-scar
patterns are quite distinct from the typical campylocythereine pattern, which, as mentioned above,
consists of a near-vertical row of four undivided adductors and a double frontal scar (see our Textfig. 1; Plusquellec and Sandberg, 1969). Campylocythereis has muscle scars that are very similar
to genera of the largely Southern Hemisphere subfamily Rocaleberidinae Bertels, 1969. Compare,
for example, the illustrations given by Omatsola (1971) with those given by Bertels (1969) for
Wichmanella and Neoveenia. We believe Campylocythereis to be more closely related to the rocaleberidines than to the campylocytherines. Omatsola (1971), of course, did not have benefit of
the normal pore data given in Puri (1974), nor had he seen Bertel’s (1969) work.
Note on “Acuticythereis” cocoaensis Krutak, 1961
The range of the tribe Campylccytherini has been extended by some authors back to the
Eocene because of the inclusion in the taxon of the late Eocene species Acuticythereis cocoaensis
Krutak, 1961. This species, we believe, is referable to the Campylocytherinae but not to the
campylocytherini. The presence of a dorsal muscle platform (see Krutak, 1961, PI. 93, fig. 11) and
the shape of the valves suggests closer affinity with Leguminocythereidini such as Triginglymus
than with genera of the Campylocytherini. We therefore exclude it from the Campylocytherini.
scars. A. Climacoidea (Climacoidea)
plueurataPuri, 1956, muscle scars of male
left valve, USNM 254586, x 925; B.
n. sp., muscle scars of female right valve,
USNM 254578, x 1OOO; C. Climacoidea
(Reticulocythereis)floridam Puri, 1960,
muscle scars of female right valve,
USNM 254582, 5, X 900.
44 J. E. HAZELAND T. M. CRONIN
The tribe Campylocytherini evolved during the latest early Miocene or earliest middle Miocene ;
the Miocene species C. (Proteoconcha) redbayensis (Puri, 1954), first appeared in the Chipola Formation of Florida. By the early Pliocene, at least eight species had evolved within the genera Campylocythere, Acuticythereis, and Climacoidea (Proteoconcha). The subgenus C . (Reticulocythereis)
first appeared in Florida and Delaware during the Pleistocene. C. (Climacoidea) has been found in
upper Pliocene deposits at Sarasota, Florida, and in Pleistocene deposits from elsewhere in southern Florida.
The stratigraphic distributions of species of Acuticythereis, Campylocythere, and Climacoidea
(Proteoconcha) in some Atlantic and Gulf Coastal Plain deposits were given by Plusquellec and
w Acuticythereis laevissima
0 Campylocythere laeva
o Climacoidea (Proteoconcha) edwardsi
Zoogeographic range of species
2-Holocene distribution of campylocytherines.
PLATEl-Figs. 1,4. Climacoidea (Climacoidea) plueurata Puri, 1956. 1. female left valve, lateral view USNM
254563, 5, x135; 4. male carapace, dorsal view, USNM 254564, 5 , X140.
Figs. 2, 5. Climacoidea (Reticulocythereis) reticulafa n. sp., Holotype, female left valve, lateral view, USNM
254572, 4, x 155; 5 . male carapace, dorsal view, USNM 254573, 2, x 155.
Fig. 3. Climacoidea (Reticulocythereis)foresteri II.sp., Holotype, female left valve, lateral view, USNM 254583,
46 J. E. HAZEL
AND T. M. CRONIN
Sandberg (1969); see also Hazel (1983). Climacoidea (Climacoidea) plueurata is known only as a
fossil from upper Pliocene and Pleistocene deposits of Florida. C. (Reticu1ocythereis)JEoridanais the
only species of the subgenus that has a known fossil record. It has been found in the Pleistocene of
southern Florida, in upper Pleistocene deposits on the St. Mary's River on the Florida-Georgia
border (Cronin, 1979), and in the Pleistocene of Delaware on the Delmarva Peninsula.
Text-figure 2 summarizes the generalized Holocene zoogeographic distribution of campylocythereine species in the northern Gulf of Mexico and on the Atlantic Coast on the basis of our
collections and published occurrence data. C . (Reticulocythereis) foresteri n. sp. is known only
from waters of the Yucatan Peninsula, whereas Acuticythereis laevissima is known from the Gulf
of Mexico off Florida and the north coast of Puerto Rico.
In terms of climate, the region between about Cape Cod, Massachusetts, and Cape Hatteras,
North Carolina, is a mild-temperate climatic zone and constitutes the Virginian faunal province
(Hazel, 1970). The region from Cape Hatteras to southern Florida contains assemblages of the
Carolinian faunal province and has a subtropical climate. The northern Gulf of Mexico is also a
subtropical climatic zone, although the ostracode assemblages from the Gulf are quite distinct
from those of the southeastern Atlantic Coast (Cronin, 1979). Southern Florida and the northern
coasts of the Greater Antilles are a transitional zone between the subtropics and tropics.
The campylocytherine zoogeographical data show several salient trends. Campylocythere is restricted to Atlantic Coast mild-temperate and subtropical regions; Acuticythereis is an inhabitant
of subtropical (off western Florida) to subtropical-tropical transitional (off Puerto Rico) areas.
All extant species of Climacoidea (Proteoconcha) inhabit inner sublittoral areas of the Atlantic and
Gulf Continental shelf, except C. (P.) edwardsi, C. ( P . ) costa and C . (P.) concinnoidea, which are
restricted to the Gulf of Mexico. The subgenus Climacoidea (Proteoconcha) is predominantly a
subtropical taxon; C . (P.) tuberculata, C. (P.) gigantica, and C. (P.) nelsonensis, however, range
into the mild-temperate Virginian faunal province. Climacoidea (Reticulocythereis) is today restricted to the Gulf of Mexico; its occurrence in Pleistocene deposits near the Florida-Georgia
border and in Delaware suggests a faunal interchange during Pleistocene time (Cronin, 1979).
Campylocythere and Acuticythereis inhabit primarily inner continental shelf environments at
depths less than about 40 m and in normal marine salinity (about 35-36 ppt (parts per thousand)).
Most species of C. (Proteoconcha) also inhabit the inner continental shelf, although C. (P.) nelsonensis, C . ( P . ) costa and C. (P.) concinnoidea are most common in polyhaline environments
having salinities of about 20-30 ppt (Grossman, 1967; Swain, 1955).
Although known only as a fossil, Climacoidea (Climacoidea) plueurata was considered characteristic of salinities greater than 30 ppt and depths less than 10 m by Puri and Vanstrum (1971).
In general, C. (Reticulocythereis) inhabits a wide range of nearshore marine environments. C.
(R.) multicarinata is common in Texas bays and lagoons in water 0 to 1.5 m deep, having salinities
of 11.3 to 50.0 ppt and temperatures 10.8" to 33.0"C (King and Kornicker, 1970). Our specimens
of C.(R.)foresteri came from a shallow brackish lagoon on the coast of Yucatan. Puri (1960, p.
PLATE2-Figs. 1 , 4 . Climacoidea (Climacoidea) plueurata Puri, 1956. 1. female right valve, lateral view, USNM
254565, 5, x140; 4. female carapace, dorsal view, USNM 254566, 6, ~ 1 4 0 .
Fig. 2. Climacoidea (Reticulocythereis) reticdata n. sp., female right valve, lateral view, USNM 254574, 4,
Figs. 3,5. Climacoidea (Reticulocythereis) jloridana Puri, 1960. 3. female carapace, right-lateral view, USNM
254579, 4, x 120; 5. female carapace, dorsal view, USNM 254575, 5, X 120.
48 J. E. HAZEL
AND T. M. CRONIN
108) described C. (R.)jloridana from “shore sand near public beach,” and Keyser (1975a, 1978)
found this species on sandy substrata in mangrove swamps off southwestern Florida, in waters
of 11 to 34 ppt salinity.
All measurements are in microns; L = length, H = height, W = width. All illustrated specimens have been deposited in the collections of the Department of Paleobiology, Smithsonian
Institution, U. S. Museum of Natural History (USNM).
Type species.-Climacoidea plueurata Puri, 1960
Diagnosis.-Distinguished from other campylocytherine genera by its low number of normal
pores, its lower number, uneven distribution, and relatively long length of radial and false radial
pore canals, its small shallow anterior vestibule, its subovate to subquadrate shape, and its steep
anterior conical tooth and deep round postjacent socket in right valve.
Remarks.-We include three subgenera in the genus Climacoidea Puri, 1956: C. (Reticulocythereis) Puri, 1960, characterized by its regular reticulation and posteroventral alate projection,
C. (Climacoidea) Puri, 1956, characterized by its extremely well developed curved carinae, and
C. (Proteoconcha) Plusquellec and Sandberg, 1969, characterized by its smooth to variably pitted
Stratigraphic Range.-Lower?, middle Miocene to Holocene.
Diagnosis.-Characterized by extremely well developed curved carinae, which parallel and in
places overlap the valve margin. Carapace variably reticulated between carinae.
Remarks.-At present, C. (Climacoidea)plueurata Puri, 1956, is the only species known in this
Stratigraphic Range.-Upper Pliocene to Pleistocene.
PLUEURATA Puri, 1956
(Pl. 1, figs. 1, 4; P1. 2, figs. 1, 4; P1. 3, fig. 1; P1. 4, figs. 3,4; P1.5,figs. 1,2; Text = fig. 1 A)
Climacoidea plueurata F’URI, 1956, p. 275, 276, PI. 36, figs. 5-12.
Climacoidea pleurata (sic) Puri. PURI AND VANSTRUM,
1971, p. 440, fig. 4.
PLATE3-Fig. 1. Climacoidea (Climacoidea) plueurata Puri, 1956, male left valve, lateral view, USNM 254567, 4,
Fig. 2. Cfimacoidea (Reticulocythereis) reticulutu n. sp., male left valve, lateral view, USNM 254576, 2, x 175.
Figs. 3,5. Climacoidea(Reticu1ocythereis)foresteri n. sp. 3 . male left valve, lateral view, USNM 254584, 10,
x 120; 5. female carapace, dorsal view, USNM 254585, 10, x 110.
Figs. 4,6. Climacoidea (Reticulocythereis)jloriubna Puri, 1960.4. male carapace,left-lateral view, USNM 254580,
6, x 130; 6. male carapace, dorsal view, USNM 254580, 6, x 135.
50 J. E. HAZEL
AND T. M.CRONIN
Remarks.-The development of intercarinae reticulation varies in this species, but the regions
between carinae are never smooth.
Stratigraphic Range.-Upper Pliocene to Pleistocene.
Occurrence.-Localities 1, 2, 3, 4, 5, 6A, 7, 8, 9, 1 1 .
Dimensions.-USNM 254563, female left valve, L = 620, H = 370; USNM 254564, male carapace, L = 605, H = 340, W = 320; USNM 254565, female right valve, L = 600, H = 325; USNM
254566, female carapace, L = 630, H = 375; USNM 254567, male left valve, L = 605, H = 335;
USNM 254568, male left valve, L = 590, H = 335; USNM 254569, female right valve, L = 630,
H = 345; USNM 254570, male right valve, L = 625, H = 320; USNM 254586, male left valve,
L = 585, H = 350.
Plusquellec and Sandberg, 1969
Type Species.-Proteoconcha proteus Plusquellec and Sandberg, 1969 (= Acuticythereis neE
sonensis Grossman, 1967)
Diagnosis.-Characterized by smooth to variably pitted surface; pitting of some species varies
among and within single populations.
Remarks.-C. (Proteoconcha) nelsonensis Grossman, 1967, and C.(P.) multipunctata (Edwards,
1944) have pitted valves; other species are smooth. Species of C. (Proteoconcha) can be distinguished from one another primarily on the basis of carapace shape and the number and arrangement of anterior radial and false radial pore canals (Plusquellec and Sandberg, 1969).
Stratigraphic Range.-Lower ?, middle Miocene to Holocene.
Type Species.-Reticulocythereis JIoridana Puri, 1960
Diagnosis.-Characterized by regular subquadrate to polygonal reticulation over entire carapace, arranged longitudinally dorsally ; it possesses a variably developed posteroventral alate projection.
Remarks.-Species of C. (Reticulocythereis) are distinguished from one another on the basis
of carapace size and shape, development of the posteroventral alate projection and details of
Stratigraphic Range.-Pleistocene to Holocene.
FLORIDANA Puri, 1960
(Pl. 2, figs. 3, 5; P1. 3, figs. 4, 6; P1. 4, figs. 5, 6; P1. 5, figs. 5, 6; Text-fig. 1C)
?New genus 1, n. sp. 1, PURIAND HULINGS,1957, fig. 11, Clastic Province No. 12.
Reticulocythereis.j?oridanaPURI,1960, p. 126, P1. 1, figs. 3,4; Text-fig. 25; PURI,1974, P1. 5, fig. 9; ?P1. 3,
fig. 1; KEYSER,
1977, p. 69, P1.3, figs. 8-13; KEYSER,1978, p. 214, fig. 4, No. 24; CRONIN,
1979, p. 148,
P1. 17, fig. 2.
?Protocytheretta multicarinata (Swain, 1955). BENDAAND PURI, 1962, p. 339, PI. 3, figs. 11, 12.
Diagnosis.-Characterized by moderate size, a carapace that tapers posteriorly more than other
1, 2. CIimacoidea (Reticulocythereis) reticulata n. sp. 1. female left valve, internal view, USNM
254577, 4, x 102; 2. female right valve, internal view, USNM 254578, 2, x 112.
Figs. 3, 4. Climacoidea (Climacoidea) plueurata Puri, 1956. 3. male left valve, internal view, USNM 254568, 4,
~ 9 8 4.
; female right valve, internal view, USNM 254569, 2, x 112.
Figs. 5, 6. Climacoidea (Reticulocythereis) floridana Puri, 1960.5. female left valve, internal view, USNM 254581,
4, x 102; 6. female right valve, internal view, USNM 254582, 4, x 116.
Figs. 7, 8. CIimacoidea (Reticulocythereis) foresteri n. sp. 7. male left valve, interior view, USNM 254584, 10,
x 90; 8. male right valve, interior view, USNM 254571, 10, x 100.